Why is this a receiver type mismatch when it seems to match what I see in the Gradle docs? - gradle

Question

I'm converting a build from Buildr to Gradle.
So far I have the following build script:
repositories {
jcenter()
}
allprojects {
version = "0.8.1-SNAPSHOT"
group = "org.trypticon.hex"
}
subprojects {
apply(plugin = "java-library")
apply(plugin = "maven-publish")
apply(plugin = "signing")
configure<JavaPluginExtension> {
sourceCompatibility = JavaVersion.VERSION_11
withJavadocJar()
withSourcesJar()
}
dependencies {
"testImplementation"("junit:junit:4.13")
}
configure<PublishingExtension> {
repositories {
maven {
url = uri(if (version.toString().contains("SNAPSHOT")) {
"https://oss.sonatype.org/content/repositories/snapshots"
} else {
"https://oss.sonatype.org/service/local/staging/deploy/maven2"
})
credentials {
username = System.getenv("DEPLOY_USER")
password = System.getenv("DEPLOY_PASS")
}
}
}
publications {
register<MavenPublication>("mavenJava") {
pom {
// omitting a bunch of metadata unrelatted to the issue
}
}
}
}
configure<SigningExtension> {
sign(publishing.publications["mavenJava"])
}
}
When I try to build, I get this:
build.gradle.kts:124:14: Unresolved reference. None of the following candidates is applicable because of receiver type mismatch:
public val PluginDependenciesSpec.publishing: PluginDependencySpec defined in org.gradle.kotlin.dsl
IntelliJ says that the types match and shows no error.
I started with code from the Gradle docs which said to use this:
signing {
sign(publishing.publications["mavenJava"])
}
But that fails when inside a subprojects block.
Using:
Gradle 6.8
Java 11.0.3
Further investigation:
I tried splitting the lines out to see exactly which bit the issue was on.
configure<SigningExtension> {
val e: PublishingExtension = publishing
val p: Publication = e.publications["mavenJava"]
sign(p)
}
The error points directly at publishing on the first line. Hovering over it in IDEA, it helpfully tells me that Project.publishing is a PublishingExtension, so the call shows no error. Now the question is, why is it fine when inspecting the file, but fails at runtime? I thought this was exactly the kind of thing switching to Kotlin was going to stop. :(

Answer 1

I had a similar problem, which I fixed by writing the following code:
configure<SigningExtension> {
val pubExt = checkNotNull(extensions.findByType(PublishingExtension::class.java))
val publication = pubExt.publications["your_publication"]
sign(publication)
}
In your case, your_publication should be replaced with mavenJava.